Postscript: Rising college educational attainment rates positively correlate with rising per capita income. Economist Joe Cortright implied a causal relationship between the two in crafting the "Talent Dividend" initiative. Concerning economic development, that's the Portland Way. Use cool amenities to attract/retain a college-educated workforce. Voila, per capita income will go up. In Portland, the talent dividend is yet to materialize. In Pittsburgh, it has:

"[David Albouy, an economics professor at the University of Illinois,] told me that he has always wondered why Portland doesn’t invest more in its institutions of higher education. If you took Portland’s quality of life and citizens, he said, and added Pittsburgh’s universities, you would come out with a world-class city."

That tells me that Albouy understands the causal relationship between college educational attainment rate and per capita income, while Cortright does not.